Decomposition of Cyanogen Chloride by Using a Packed Bed Plasma Reactor at Dry and Wet Air in Atmospheric Pressure

The decomposition rate of CNCl in a BaTiO₃-filled Packed Bed Plasma Reactor was studied as a function of AC input power, power frequency, residence time in the reactor, and inlet flow rate. The decomposition rate was compared with those of CH₃CN and CCl₂CHCl. Under the condition of 6.7 Wh/m³ specific energy den- sity, the decomposition rate of CNCl was found to be 50%, which is lower than those of CH₃CN and CCl₂CHCl at the same or similar conditions. At a higher frequency of the power input system, the decomposition rate of inlet gas becomes lower due to a decrease in field strength for the same level of power. And, under the same level of input power, a higher decomposition rate was obtained at an increased residence time. The relation between gas decomposition rates stemmed from the electron–molecule collision and bounding energy within the molecule. The decomposition ratio of CNCl was lower than those of CCl₂CHCl and CH₃CN because the bond strength of the weakest bond in the molecule is higher. In order to test the decomposition efficiency of CNCl with catalytic packing material in a plasma reactor, the catalyst of γ-Al₂O₃ and Pt/γ-Al₂O₃ was packed in the packed bed plasma reactor. Although byproducts were formed, the plasma-catalyst hybrid reactor containing Pt/γ-Al₂O₃ showed a higher efficiency in CNCl decomposition as shown in the decomposition rate of above 99% in 0.3 kWh/m³.